textproduct: Rapid City

KEY MESSAGES

- Cold again Wednesday morning, but gradually warming up towards the weekend.

- Isolated chances for precipitation mid-week, better chances late Thursday into Friday.

- Much warmer temperatures settle in over the weekend into next week.

DISCUSSION

(This Evening Through Tuesday) Issued at 125 PM MDT Tue May 19 2026

Current upper air models show the upper trough axis east of the forecast area this afternoon, with west northwest flow over the region. 19Z surface analysis depicts high pressure over Wyoming, weak surface trough over central MT. Satellite shows widespread CU across the forecast area, with little vertical extent. Temperatures currently sit in the 40s to mid 50s with light winds predominantly out of the northwest.

Brief shortwave ridge settles in Wednesday into Thursday, prompting a slow warming trend with mostly dry conditions. Weak surface trough in MT passes through Wednesday. This forcing may spark some isolated to showers/storms but no significant QPF is expected through the first half of Thursday. As ridge shifts eastward, troughing once again slides across the Rockies and into the northern and central plains. Synoptic forcing will prompt widespread precipitation the latter half of Thursday into Friday. Current NBM probabilities for precip >= 0.25" has a wide swath of 60 to 80 percent over most of western SD, excluding far northwestern SD. Based off the current track of this system, highest QPF amounts are expected in the Black Hills and southwestern SD

Precipitation is expected to taper off from west to east later Friday, and upper ridge slowly builds over the weekend. Expect highs to jump into the 70s and 80s by Saturday, and stick around through the forecast period.

AVIATION

(For the 00Z TAFS Through 00Z Wednesday Evening) Issued At 502 PM MDT Tue May 19 2026

VFR conditions expected through most the forecast period. The exception will be south central SD Wed. MVFR cigs will move into the area there as an impulse skirts the region.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Frost Advisory from midnight MDT /1 AM CDT/ tonight to 8 AM MDT /9 AM CDT/ Wednesday for SDZ002-012>014-027-030>032-041>044- 046-047-049-073-075>078. WY...Freeze Warning from 2 AM to 8 AM MDT Wednesday for WYZ055-056- 058>060.